brennan is the administration's point person on drones, the man who signs off on the kill list. >> i suggest to you that these targeted strikes against al qaeda terrorists are, indeed, ethical and just. >> reporter: the use of drones has grown 700% under the obama administration. we learned just yesterday, that america has a secret base in saudi arabia, used to send drones throughout the region. lawmakers will discover about a document that says american citizens tied to al qaeda can be killed if a high-level official believes the target poses an imminent threat. but the government can do so without having clear evidence. human rights advocates disagree. >> that justifies, essentially, a claim that the executive branch can be judge, jury and executioner. >> reporter: drone strikes have become controversial. in pakistan alone, there have been more than 300 drone strikes in the last decade, killing thousands of terrorists. but also more than 300 civilians. the retired general who once ran the military's drone strike program, thinks there should be discussion about their use. >> if the